BEAMNOVA Metal Drum Heater 110V Pail Heating Band for 55 Gal Barrel 5 * 68.5 inch Honey Oil Silicone Rubber Heating Band Heavy Duty Temperature Controller: Amazon.com: Industrial & Scientific
BriskHeat FGPDHC55120 55gallon, Full Coverage, Drum Heater - 120 V from Cole-Parmer
BriskHeat Plastic Drum Heater - 55-Gallon, 300 Watt, 120 Volt, Model Number DPCS15: Drum And Pail Heaters: Amazon.com: Industrial & Scientific
Drum Induction Heater - fits to 55 gallon drums or smaller ones - Thermosafe Type A - 2750 Watt